Dalarna, Sweden — The arrest in Sweden of a Uighur exile on charges of "refugee espionage" last month hints at how far China's efforts may extend to keep tabs on the ethnic group it considers a threat to the state.

The Swedish Security Police (Säpo) arrested Babur Mehsut, a Uighur exile and naturalized Swedish citizen, on June 4. According to Tomas Lindstrand, chief prosecutor of Sweden's International Prosecutor's Office, the crime involves the "unlawful acquisition and distribution of information relating to individuals for the benefit of a foreign power," in this case, China.

Mr. Lindstrand states that the alleged crimes occurred from January 2008 to June of this year in Sweden and abroad. Mr. Mehsut is known to have attended a meeting of the World Uyghur Congress in Washington this May.

Analysts and Uighur exiles say that China has an intelligence network aimed at monitoring developments in the Uighur diaspora and trying to sow dissension within and among Uighur groups. There is also wide agreement that Uighur operatives involved in the network are often coerced into it by the Chinese authorities.

Uighur expatriates can face "threats" to their family members still living in China, with the Chinese authorities seeking "to stop behavior they don't like, or encourage behavior they want," says Gardner Bovingdon, a Central Eurasia expert at Indiana University in Bloomington.

Diplomatic row ensues

Shortly after Mehsut's arrest, Sweden expelled a Chinese diplomat; Beijing promptly expelled a Swedish diplomat in return. Repeated attempts to get a comment by Chinese officials at Stockholm's Chinese Embassy have proved fruitless, and the Swedish Foreign Ministry had no comment on either Mehsut's arrest or the diplomatic expulsions.

Ministry spokeswoman Cecilia Julin did, however, say that the ministry is acting in accord with the statement on Säpo's website that "democratic states do not engage in refugee espionage."

The tensions between China and Sweden over Sweden's Uighurs date back to at least November 2007, when Adil Hakimjan, one of the Uighurs who had been incarcerated at Guantánamo, the United States prison camp, was released and sought political asylum in Sweden. Sweden has a Chinese Uighur population of about 100.

According to Lindstrand, Mehsut allegedly began spying for the Chinese two months after Mr. Hakimjan's arrival here, in January 2008.

"The timing has to be significant," says Professor Bovingdon. The Guantánamo Uighurs are "major playing pieces in the game ... to persuade people that there are Uighur terrorists, and that therefore Uighur dissidents should be identified as terrorists." He adds that Beijing might have sought Uighur-to-Uighur statements about the US or the war on terror to bolster its claims.

China called Hakimjan a "terrorist," though both Sweden and the US officials say that he is an innocent refugee. Sweden gave Hakimjan asylum in April.

Dilshat Rashit, a spokesman for the World Uyghur Congress who resides in Sweden, says that Mehsut had been in Hakimjan's company on a number of occasions.

When contacted about the Mehsut case, Hakimjan declined to comment on it, but noted that he "hopes the Chinese government will find the compassion to allow his wife and children to leave China and join him in Sweden."

Mehsut's arrest causes surprise

Uighurs interviewed for this story, who knew Mehsut, expressed shock that he had been arrested for spying.

When asked if spying was a problem in the Uighur diaspora, Mr. Isa acknowledges that it is, and spoke of the pressures felt by parents and relatives living in China.

'We will hurt your family'

Bovingdon says that, although Mehsut's arrest is the first he's aware of regarding spying in the Uighur diaspora, it is widely believed that such spying has long transpired.

"The Chinese government has sent people from China, including Xinjiang, out into the world to keep tabs on other people. There's no question about this," says the professor. He also notes that, in the past, he has been contacted by US authorities concerning an investigation somewhat similar to Mehsut's.

He also describes accounts of expatriate Uighurs receiving phone calls from people who identify themselves as Chinese intelligence sources saying that "unless you do something for us, we will hurt your family."

According to Patrik Peter, press secretary for the Swedish Security Police, the investigation of Mehsut is ongoing and a trial could begin as early as September.

Björn Hurtig, Mehsut's attorney, says he can give no comment about the case "because of both my client's wishes and the court order."